Mating Advantage of Multiple Male Ornaments in the Barn Swallow Hirundo Rustica Gutturalis Hasegawa, Masaru and Arai, Emi and Watanabe, Mamoru and Nakamura, Masahiko, Ornithological Science, 9, 141-148 (2010), DOI:http://dx.doi.org/10.2326/osj.9.141